Experimental research on axial force quantitative loss law of anchor bolt in blasting in high impact danger roadway

In terms of the problem that in rockburst mine the pressure release blasting with unreasonable parameters presently leads to support damage,and reduces the effect of rockburst prevention,using bolting quality non-destructive testing technology,the axial force quantitative loss law of anchor bolt in blasting in high impact danger roadway was quantitatively analyzed. The analysis revealed the scope and extent of bolts axial force loss caused by blasting with var- ying doses of explosive. And when blasting dose is equal to or greater than 6 kg,axial force loss attenuates exponential- ly with the distance from the explosive center,but there are also possible that partial loss suddenly increases. Axial force loss rate in blasting is associated with anchor position,which is more obvious when the distance between source and anchor position is shorter. With the increase of explosive charge,the axial force loss rate of bolt anchor increases, which is faster when the charge is larger. Considering the axial force loss law of the anchor of blasting and the effect of blasting pressure relief in coal seam,the result of blasting parameter optimization is 12 m hole depth and 6 kg charge in the high impact danger roadway of a mine of Inner Mongolia,the effect of its application is ideal. Also,the in-situmeasurement method of pressure relief blasting parameter optimization in coal mine was established.